The IEEE 802.1X protocol is an access control mechanism for a LAN port, which is widely used in Ethernet. The protocol provides an authentication method and a security function within the Ethernet.
The 802.1X protocol is a port-based network access control protocol. “port-based network access control” means that authentication of a user device and access to a LAN by the user device is controlled at a port of a LAN access device. If a user device connected to the port passes the authentication, then it can visit resources in the LAN. If user device connected to the port does not pass the authentication, then it can not visit the resources in the LAN.